so I have a 20 gallon long planted its has 20 red cherry shrimp 5 ottos 5 pigmy corys mts hundreds nerite snails about 10 12 so my question is I have month old betta fry I was wondering if I could put them in the planted tank

Are the nerites the one's I sent you? I don't know if it would make a difference, but if they are they aren't nerites, they are ivory apple snails. I think it should be fine putting a small amount of fry like that in it though. Just watch the parameters and water changes as normal.